a. Field of Invention
This invention relates to a wheelchair navigation system, and more particularly to a computer-controlled power wheelchair navigation system that allows a person to navigate through a location with pre-established paths, and with voice or manually activating the computer.
b. Description of Related Art
A significant population of severely disabled people require mobility assistance in daily living activities beyond what is available in conventional powered wheelchairs. The present invention is aimed at a segment of that population, those unable to manually guide the movements of powered wheelchairs, to provide them with autonomous navigation capabilities in repetitively used environments such as homes, offices, hospitals, and public buildings and spaces.
There are a number of navigational methods that already exist for autonomous and semi-autonomous vehicles. Current navigational systems for semi-autonomous vehicles usually have controls such as a joystick or an ocular device, and employ overriding features such as obstacle or collision avoidance. Some autonomous systems utilize path-following methods such as a magnetic strip, optical strip or targets to provide paths from an origin to a destination. These methods have difficulty handling multiple and intersecting paths, if they can handle them at all.
There are three systems specifically identified in the prior art, all of which differ from the present invention. A robotic wheelchair system, commonly known as the WHEELSELSY, developed by the Massachusetts Institute of Technology Artificial Intelligence Laboratory, operates as a semi-autonomous system that is capable of being controlled by head and eye movements of the rider.
Another wheelchair system known as NavChair® is an adaptive shared control system that is semi-autonomous. The NavChair® uses guidance command from the rider and exerts control in areas such as obstacle avoidance or object approach.
The Wheelchair Project also has a system that uses landmark recognition and obstacle avoidance as well as interaction across a spectrum of automations from low level motion guidance to selection of destination wherein the wheelchair delivers the rider.
None of these known assistance devices are fully autonomous operations. Moreover, none of these known assistance devices permit avoidance of wheelchair collision with obstacles during navigation of the wheelchair through a taught trajectory while allowing for close approach of the wheelchair to solid bodies present during performance of teaching functions. They do, however, share many common features, including adaptability to a multitude of different vehicles, varying levels of operator control authority, and obstacle avoidance.
The autonomous navigation system of the present invention was developed for use in rehabilitative or therapeutic environments as well as domestic and vocational circumstances. It can also be modified for use in independent mobile circumstances for the severely disabled such as public access buildings like museums and airports. Secondary applications for autonomous transport are also foreseeable, although not specifically identified herein.